1. Field of the Invention
The invention relates to a device for restricting or controlling and regulating the movement of remote-controlled parts of a vehicle bodywork as disclosed herebelow. Particularly advantageous is its use as collision protection for window winders, sunroofs, doors or flaps.
2. Background Information
Devices for controlling and more particularly monitoring the closing process of motorized parts, such as doors, flaps or window panes of motor vehicles are known and use the most varied of technical principles for this purpose. A difference is made here between those which are linked with direct bodily contact and those systems which operate fee of contact.
In German Laid Open Patent Application No. 22 46 337 a safety device for motor closable openings is disclosed which measures a specific value of an acoustic source eg. the sound intensity wherein the acoustic receiver is connected to the acoustic source by a transmission path conducting the air-borne sound. The transmission path can be an elastic hose mounted in the area of a closing edge. When it is deformed through an obstruction the sound intensity reaching the received is reduced. An evaluator device reacts thereto with a setting command to the motor.
The disadvantage of this safety device is the danger of damage to or destruction of the transmission path when it is used as a jamming protection for the window winder of a vehicle.
Furthermore fixing the hose on the circumferential edge of the pane leads to fastening problems, in the area of the right-angled pane edges to transmission problems. Furthermore inside the guide frame there is the danger of unintended release of the safety device.
German Patent Publication Published for Opposition Purposes Number 24 32 063 describes a device for monitoring the door closing process in local transport vehicles by using the principle of a light beam. Radiation source and sensor are mounted substantially in one plane in the area of the closing edge. The transmission path inside the relatively large volumed elastic cover element is completed by a reflector at the opposite end of the closing edge. During deformation of the cover element the light transmission is dampened which leads via the sensor to the proposed reaction of the device.
A disadvantage is that the described device cannot or only after fitting expensive internal reflectors be used for monitoring curved closing edges as would be necessary for the window pane of a vehicle.
From German Patent Number 27 19 955 is known a contact-free field sensor for detecting persons or objects in front of edges greater than moving along a straight line. The antenna capacitors of the sensor detect an asymmetrical capacity change through approaching objects and lead to control commands via an evaluator device.
Unfortunately field sensors often do not have a sufficiently restricted (narrow) operating range so that reactions can also be triggered by objects which do not lie directly in the direction of movement of the closing edge. By way of example when using this safety system as jamming protection for electric window winders in motor vehicles the approach of the head or shoulder of a passenger towards the pane can lead to a reverse movement thereof.
German Patent Numbers 30 34 118 and 31 36 746 describe a process for electronically monitoring the opening and closing process of electrically operated assemblies wherein an electric setting member can be controlled from the time changes in the characteristic values of the assembly and their evaluation in a micro-computer. In one of the closing areas divided into several sections, during the closing process the speed of the assembly is continuously detected and compared with a boundary value. If the boundary value is exceeded then a temporary reverse movement is carried out followed by a complete switch-off.
This process very reliably detects jamming but as a result of the in part considerable mass inertia forces acting during the movement or braking of the displaceable object, the system reacts relatively sluggishly. Therefore quite large forces can act on the jammed objects.
The object of the invention is to develop a device
which is also suitable inter alia for use as a separate or additional collision protection wherein the release force is to be significantly reduced and wherein the collision protection should only respond in the area of immediate danger;
whose functional reliability is not impaired by outside influences such as dirt, water, ice, wear and ageing of the parts;
which manages without using separate switches mounted locally separated from the remote-controlled part; and
which increases the operating comfort, more particularly by linking ergonomic and logical operating sequences.
According to the invention this is achieved through a device with at least one electromechanical converter as actuator and at least one mechanical-electrical converter as sensor, as well as an electronic evaluator/control device wherein the actuator and sensor are mounted on a common i.e. cohesive acoustic transmission path which is part of a remote-controlled part eg. a window pane or a tailgate of a motor vehicle, and which is particularly accessible to or can be brought into contact with a person, his hands or even inanimate objects. The actuator produces in the transmission path acoustic surface wavers (Rayleigh waves) of which the sensor detects at least one characteristic value eg. the amplitude or frequency and passes it on to the evaluator/control unit.
By altering the properties of the transmission path it may be necessary to adapt the device according to the invention. Depending on the pane guide and pane position the changed external conditions can lead to damping of the signal as a result of damage, dirt or ice and also to reflection of the signal. According to the invention the adjustment is achieved by increasing and reducing the output capacity and/or frequency of the actuator. In order to minimize the technical expense the actuator and sensor are advantageously designed as one integral functional unit wherein their functions are set timewise in succession. Piezo-crystals are suitable for this purpose.
However the use of several actuators and sensors can also be suitable. This makes it possible to diagnose the ageing of the transmission path or of the parts connected therewith (eg. the guide or sealing areas of a window pane or a flap of a vehicle) or even a temporarily altered state eg. through ice. The sensitivity of the system can easily be adapted to the new external conditions. This advantageously happens automatically by means of an electronics unit.
The application of one (or where necessary more) defined changeable areas on the transmission path which in itself is free of undesired changeable areas can be advantageous in order to increase the system sensitivity. The changeable area alters the spreading characteristic of the surface waves in a predetermined measure and thus serves as the reference point on the transmission path.
Various types of unstable areas can be used. As a rapid expansion or restriction of the transmission path orthogonally to the scattering direction of the surface wave they suddenly change the absorption degree or the reflection behavior. Further variations are inward or outward kinks, waves or edges in the transmission path. The radius of the unstable areas lies in the order of the wave length of the first harmonic surface wave and is as a rule much smaller than this itself.
If the transmission path is formed by a glass surface, eg. the circumferential end face of a window pane, then notches are particularly good for influencing the surface waves. Their shape can be adapted very well to the desired effects. Thus their shape and depth can have an influence on the ratio of the reflection part to the absorption part. Also the production of a diode effect, wherein the surface wave can pass the notch with only a slight damping in one direction whilst the surface wave in the other running direction as a result of a (quasi) total reflection is prevented from travelling on the other side of the notch.
For a direction-indifferent behavior, symmetrical notch geometries are used which have roughly the shape of an isosceles triangle. Asymmetrical notch geometries however lead to a ratio of reflection to absorption which is reversed in dependence on the direction. For example if a surface wave runs onto only a slightly inclined wedge surface (at a flat acute angle to the plane of the transmission path) then in each case a further transmission of the surface wave takes place in the original direction. Its amplitude is naturally reduced corresponding to the damping and reflection behaviour of the edge.
If the surface wave however strikes a wedge surface which is set up at a steep angle and includes with the transmission direction an angle of about 90 deg. or more, then with a simultaneously sufficient notch depth it results in total reflection. On the other hand a surface wave of the other scattering direction can pass the notch (diode effect).
The use of such notches makes it possible to increase the sensitivity of the measuring system when a part of the transmission path does not belong to the monitoring area, but external conditions can considerably influence its transmission properties. An example of this is the vertically aligned sealing and guide area of a vehicle window pane whose absorption properties can vary considerably in dependence on the position of the window pane, the tension of the pane and numerous environmental factors. The possibility of cutting out or evaluating these areas separately is often of decisive importance for a reliable monitoring of the freely accessible upper edge of the pane. A considerable increase in the sensitivity is achieved through the difference formation of the signals of different areas defined by notches. In order to increase and adapt the measuring and evaluating system further, a calibration path can be provided between the upper and lower stop position by applying a learning program.
An evaluation of the sealing and guide areas can also be used to control the drive output in order to ensure constantly uniform kinematics. The use of two transmitter/receiver units which are each preferably designed as integral piezo-ceramic vibrators leads to a redundantly operating device. Comparing the independently evaluated measuring results increases the reliability of the statement. More particularly, with an overall symmetrically designed device, the two measuring systems can also operate in cold operating redundancy.
An advantageous application of the device according to the invention is its use as collision protection for electrically operated window winders, sunroofs, doors or flaps. The transmission properties change when a colliding object contacts the transmission path. The sensor and control unit registers this and causes corresponding setting commands. A complete or partial reversing of the displacement movement (in the case of window winders), or jamming in the position reached can be obtained.
Further uses can exist in the control of the end and intermediate positions of a displacement part. It is thus possible for example to xe2x80x9csoftxe2x80x9d start the upper and lower end position or to control short-stroke lowering of the side pane which facilitate the closing of doors. Furthermore the function principle of the invention can dispense with the use of switches because the mere contact of one or more proposed areas in the transmission path triggers the desired switching effects.
When using the device according to the invention for a collision protection those faces which can be influenced from outside and which substantially represent the closing faces are suitable as the transmission path. Their plane runs mostly at an angle to the direction of movement of the remote-controlled component. If this component is for example a window pane of a vehicle then the circumferential end face which connects the outer and inner pane plane is used as the transmission face. The actuator and sensor or a corresponding function unit can advantageously be mounted on a component of the transmission path which is not directly accessible, which cannot be seen directly and which does not destroy the path of movement of the window. The lower edge of the pane would be suitable for this. If, however, the actuator and/or sensor are to be used in the area of the closing faces (e.g. upper edge of the pane) then the energy and signal leads are provided on the edge of the disc in the form of printed conductor plates.
Coupling and uncoupling the energy is carried out either by conductor plates or cables or wireless (e.g. inductively) when the required energy density and reliability of the structural elements permit this.
One or more of the following principles can be used to evaluate the signal: running time measurement, amplitude modulation, phase and frequency modulation. The requirements for reliability (also redundancy) and sensitivity are decisive for this.